A nonaqueous electrolyte battery in which charge and discharge are performed by migration of lithium ions between a negative electrode and a positive electrode is actively researched as a high energy-density battery.
In addition to the use as a power supply for small electronic devices, the nonaqueous electrolyte battery is expected to be used as a medium to large power supply such as in-vehicle use or stationary use. For such a medium to large-scale use, the nonaqueous electrolyte battery is required to exhibit excellent life characteristics and a high-level safety.
Examples of candidates for positive electrode active materials for nonaqueous electrolyte batteries that can exhibit excellent life characteristics and high-level safety include olivine-type compounds such as an olivine-type lithium-iron phosphate and an olivine-type lithium-manganese phosphate. On the other hand, examples of candidates for negative electrode active materials include a spinel-type lithium titanate.